PARTS OF A SOUND SYSTEM

1. PARTS OFA SOUND SYSTEM MICROPHONE CHOICES MICROPHONE PLACEMENT SPEAKER ALIGNMENT ACOUSTICS OF THE ROOM

2. Vocabulary for the week... • XLR – Multipin metallic audio connector. XLR Cables are used to connect microphones. • Amplifier – The part of the sound system that actually magnifies or “amplifies” the sound... in other words, it makes stuff louder. • Power Amplifier – Converts sound signals of line level (approx. 1 volt) into tens of volts, with currents of around 1 Amp to drive speakers. • Phantom Power – Used by condenser microphones to supply power to them in order to work. Called “phantom” because it is “invisibly” carried down the same microphone cable as the sound signals. • Speakers – Devices that change electrical signals to audible sound. • Mixer – A console, or other device that blends audio signals into composite signals. • Monitors – Speakers facing back onto the stage. • Microphone – A transducer which converts sound pressure waves into electrical signals. • Stereo – A recording or reproduction of at least two channels where positioning of instrument sounds left to right can be perceived.

3. MICROPHONE CHOICES There are several types of microphones to pick from. They can be broken down into two main categories... Dynamic Microphones Condenser Microphones

4. DYNAMIC MICROPHONES Dynamic microphones are simply put, tanks. They can withstand abuse and the elements better than condenser microphones. Dynamic microphones have a smaller frequency range compared to condenser microphones, and will be better suited for high pressure sound levels (guitar racks, drums, etc.) The sound quality from a dynamic microphone is typically less than that of a condenser microphone. A dynamic microphone does not need a power supply (condensers do). Popular dynamic microphones include the SHURE SM 57 and SM 58.

5. CONDENSER MICROPHONES Condenser microphones are on the opposite end of the spectrum from dynamic microphones. First of all, condenser microphones need a power source. This source is known as “phantom power.” It is important to know if your soundboard supports phantom power because if not, you cannot use condenser microphones. Condenser microphones have a much broader frequency range compared to dynamic microphones. Condenser microphones also produce a higher quality of sound than dynamic microphones. They are also much more fragile and more expensive.

6. DIAPHRAGMS Condenser microphones come in two styles... Large Diaphragms and Small Diaphragms. Large Diaphragm condenser microphones are use for... • Vocals • a warmer, deeper sound Small Diaphragm condenser microphones are used for... • overheads • string instruments • overall recording (full stage setups) • all purpose recording As a default setting, use a small diaphragm mic for most applications except vocals.

7. MICROPHONE PLACEMENT Depending on what you are doing, the placement of the microphone changes... Let’s talk about setting up sound for a marimba... First, you need to know the characteristics and timbre of the instrument. Second, you need to select what TYPE of microphone to use and how many. Third, you need to know WHERE to place the microphone(s).

9. CONTINUED... Now that you have done those three things lets talk about cables... Each microphone cable (aka. XLR Cable) has two different ends... a male and female end. The male end of the cable (3 pins) hooks into the soundboard and the female end (3 holes) goes into the microphone. That’s it... not too complicated so far...

10. SPEAKER ALIGNMENT Speaker Alignment is a VERY important part of a sound system. Look at our synthesizer cart... the speakers are not aligned properly on this cart. Knowing where your sound will be travelling is a big deal. If it is going to a small audience (like in this room) then our speakers are fine on the cart as is. If the audience is larger (like in the auditorium) you will not get good sound characteristics from our cart... the speakers need to be repositioned.